[PATCH] EDAC: altera: Delete an inappropriate dma_free_coherent() call in altr_sdr_mc_err_inject_write()

[Salah Triki]

`dma_free_coherent()` must only be called if the corresponding
`dma_alloc_coherent()` call has succeeded. Calling it when the allocation
fails leads to undefined behavior.

Add a check to ensure that the memory is only freed when the allocation
was successful.

Signed-off-by: Salah Triki <salah.triki@xxxxxxxxx>
Fixes: 71bcada88b0f3 ("edac: altera: Add Altera SDRAM EDAC support")
Cc: Markus Elfring <Markus.Elfring@xxxxxx>
Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: Robert Richter <rric@xxxxxxxxxx>
Cc: linux-edac@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
---
 drivers/edac/altera_edac.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index cae52c654a15..7685a8550d4b 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -128,7 +128,6 @@ static ssize_t altr_sdr_mc_err_inject_write(struct file *file,
 
 	ptemp = dma_alloc_coherent(mci->pdev, 16, &dma_handle, GFP_KERNEL);
 	if (!ptemp) {
-		dma_free_coherent(mci->pdev, 16, ptemp, dma_handle);
 		edac_printk(KERN_ERR, EDAC_MC,
 			    "Inject: Buffer Allocation error\n");
 		return -ENOMEM;
-- 
2.43.0